Paper-based map designers have always faced a Hobson's choice: they could choose to include greater amounts of detail and create a map that was either too large or too cluttered, or they could choose to remove details and create a map that did not contain the relevant information needed by its users. Digital maps accessed via a computing device do not present such a choice. Instead, because the level of detail displayed can be adjusted by the user, such as through a zoom function, digital map designers can include as much detail as can be conveniently and efficiently created, stored and accessed. User control of the amount of detail displayed, and the geographic area displayed, enables each user of a digital map to customize the displayed map for their own purposes.
However, while greater amounts of information can be efficiently consumed by the user of a digital map, and increase the user's perceived value of the digital map, the collection, maintenance and storage of such information can limit the amount and type of information typically provided by digital map publishers. Map information that frequently changes can require continuous collection and updating efforts on the part of the digital map publisher, which can be both time consuming and costly. For example, public transportation routes can frequently change and, if such details are to be part of the digital map, the digital map publisher must first monitor the appropriate sources of the public transportation routes, and must subsequently collect the new route information when it is changed and, finally, must modify the existing digital map data accordingly. Even if map information does not frequently change, the sheer quantity of information can limit the ability of the digital map publisher to provide such information. For example, satellite imagery can be useful for years before it needs to be updated. However, detailed satellite imagery can require hundreds of gigabytes of storage space and, even more costly, it can require large amounts of network throughput if the digital map is to be provided to users through a network connection.
Historically, digital maps were published via portable computer-readable media, such as floppy disks or compact disks. The storage capacity of such computer-readable media limited the amount of detail that publishers could include with digital maps. More recently, especially with the growth of the Internet and the World Wide Web, digital maps are also provided to users through network connections. Such network-accessed digital maps still suffer from storage constraints, though the quantity of storage available can be orders of magnitude larger. Furthermore, the throughput of the network connections of digital map publishers can likewise limit the amount of detail that digital map publishers can provide to large numbers of simultaneous users. For example, ultra-fast multi-gigabit connections can support only a handful of simultaneous users if each user is requesting large quantities of detailed digital map data.